Having checked the information you've sent us, FirstSpot DHCP Server didn't contain any lease record of either 192.168.11.x or the client MAC address. Futhermore, the DHCP log only shown up to 12:27 while the client obtained the IP 192.168.11.17 at 12:35.

Please double check whether the client attached to the correct AP. After that, executing the following in Command Prompt should help to obtain correct IP:
ipconfig /release
ipconfig /renew

The above shows that FirstSpot DHCP Server was trying to offer 192.168.2.x and was rejecting DHCP renew requests for those 192.168.11.x.

If what you mean by "doesn't work" after running the commands is the client still obtained 192.168.11.x, most likely there's another DHCP server offering that segment of IPs and your clients preferred to accept those offers. Please really double check this.